1. The Field of the Invention
This invention relates to solar energy collectors and more particularly to that class of apparatus which collects the rays of sun, disposing same to an area wherein a medium can be heated, such that the area is remotely located from the sun ray collecting device.
2. Description of the Prior Art
The prior art abounds with solar energy collectors, many of which collect the sun rays from various angles, concentrating same on a specific target area, usually disposed within the collection device. U.S. Pat. No. 3,182,654 issued May 11, 1965 to J. H. Culling is typical of such a device. The Culling disclosure teaches a semi-spherical object having light transmissive characteristics, concerning light rays passing into the interior of the sphere. The interior surface of the sphere is coated with a light reflective medium which permits light rays to partially pass therethrough. The target area is disposed substantially at the origin of the semi-sphere, in one embodiment of the Culling disclosure, such that light rays striking the semi-sphere in near horizontal directions and near vertical directions will reflect once from the interior surface and be directed at the target area. Additional lens or internal reflectors further widen the incidence angle of the sun, to the horizon, thereby increasing the efficiency of the device. The Culling device is limited, however, in a well defined target or heating area such that small targets only may be employed. This apparatus is useful in elevating the temperature of the target area to a great degree provided the target is small and is confined within the interior of the device.
U.S. Pat. No. 2,994,318 issued Aug. 1, 1961 to W. C. Lee discloses a reflector having the shape of a portion of a cylinder whose interior surface, having a concave shape, is juxtaposed to a tube, whose axis extends coaxially with the axis of the semi-cylinder. Light rays striking the interior surface of the semi-cylinder are concentrated on the tube causing a liquid or gaseous medium therein to be heated. It should be noted that each of the light rays eventually striking the tube approach the tube surface at diverse angles, never crossing one another or extending parallel to one another. Thus, the Lee teachings describe an apparatus which does not concentrate the rays of the sun in a reinforcement manner, but rather concentrate the rays of the sun passing through the interior of the open mouth portion of the semi-cylinder into an area equivalent to the cross section of the tube. If the diameter of the semi-cylinder were to be increased, whilst the diameter of the tube is maintained the same, a greater degree of axial alignment is required to insure that some of the collected rays would not be directed to a position not occupied by the tube. Furthermore, the Lee apparatus is functional only for those rays which strike the interior surface of the semi-cylinder within narrow angular limits relative to a line extending at right angles to the open mouth portion of the semi-cylinder.